Strawberry plant named &#39;fronteras&#39;

ABSTRACT

‘Fronteras’ is a short-day (June bearing) cultivar similar to ‘Camarosa’ (U.S. Plant Pat. No. 8,708), but with greater productivity, higher quality fruit, and earlier production; it is similar to ‘Ventana’ (U.S. Plant Pat. No. 13,469) and ‘Benicia’ (U.S. Plant Pat. No. 22,542), but with somewhat later production, a larger plant, superior fruit and quality, and better-flavored fruit.

GENUS AND SPECIES

The strawberry cultivar of this invention is botanically identified as Fragaria×ananassa Duch.

VARIETY DENOMINATION

The variety denomination is ‘Fronteras’.

BACKGROUND OF THE INVENTION

This invention relates to a new and distinctive short-day type cultivar designated as ‘Fronteras’, which resulted from a cross performed in 2008 between two unreleased germplasm accessions Cal 4.18-4 and Cal 5.165-1. Accession Cal 4.18-4 was chosen as a parent due to its very high early productivity, large and high quality fruit, and moderate plant vigor. Accession Cal 5.165-1 was chosen as a parent due to its vigorous but open plant habit and firm, large and flavorful fruit, and extended productivity.

‘Fronteras’ was first fruited at the University of California South Coast Research and Extension Center, near Irvine, Calif. in 2009, where it was selected, originally designated Cal 8.132-608, and propagated asexually by runners. Following selection and during testing the plant of this selection was designated ‘C235’. With the decision that this plant was to be released, this plant was given the name ‘Fronteras’ for purposes of introduction into commerce and for international registration and recognition. Asexual propagules from this original source have been tested at the Watsonville Strawberry Research Facility, the South Coast Research and

Extension Center, and to a limited extent in grower fields starting in 2010. The cultivar is stable and reproduces true to type in successive generations of asexual reproduction.

BRIEF SUMMARY OF THE INVENTION

‘Fronteras’ is a short-day (June bearing) cultivar similar to ‘Camarosa’ (U.S. Plant Pat. No. 8,708), but with greater productivity, higher quality fruit, and earlier production; it is similar to ‘Ventana’ (U.S. Plant Pat. No. 13,469) and ‘Benicia’ (U.S. Plant Pat. No. 22,542), but with somewhat later production, a larger plant, superior fruit and quality, and better-flavored fruit.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figures depict various characteristics of the ‘Fronteras’ cultivar.

FIG. 1 shows the general flowering and fruiting characteristics of the plant in a field planting.

FIG. 2 shows a typical leaf at mid-season.

FIG. 3 shows representative mid-season fruit.

DETAILED DESCRIPTION OF THE INVENTION

‘Fronteras’ is typical of short-day strawberry cultivars and produces fruit over an extended period when treated appropriately in arid, subtropical climates. The production pattern for ‘Fronteras’ is similar to that for ‘Camarosa’ (U.S. Plant Pat. No. 8,708), although it is slightly earlier to initiate fruiting with most cultural treatments. ‘Fronteras’ initiates fruiting slightly later than

‘Ventana’ (U.S. Plant Pat. No. 13,469) and ‘Benicia’ (U.S. Plant Pat. No. 22,542) when established in very early fall. ‘Fronteras’ will be of special interest for winter plantings, where ‘Camarosa’, ‘Ventana’, and ‘Benicia’ have been successful, and in summer plantings where ‘Chandler’ (U.S. Plant Pat. No. 5,262) and ‘Camino Real’ (U.S. Plant Pat. No. 13,079) have been successful.

Plants and Foliage:

Fruiting plants of ‘Fronteras’ are slightly taller, more erect, and more open than all of the comparison cultivars in most production environments. Comparative statistics for foliar characters near mid-season are given for ‘Fronteras’ and three comparison cultivars in Table 1. Individual leaflets for ‘Fronteras’ are to those of the comparison cultivars, and are more elongated than for ‘Benicia’. Leaves (including petioles) for ‘Fronteras’ are slightly longer than for

‘Ventana’ and ‘Camarosa’, shorter than for ‘Benicia’. Petioles for ‘Fronteras’ are generally longer than those of ‘Ventana’, ‘Benicia’ and ‘Camarosa’. The adaxial (upper) and abaxial (lower) surfaces of leaves for ‘Fronteras’ are lighter than for ‘Camarosa’ and ‘Benicia’, darker and less yellow than for ‘Ventana’ leaves at midseason. Leaves of ‘Fronteras’ have similar concavity to ‘Camarosa’, and are less concave those for ‘Ventana’. Serrations at midseason are less pointed than for ‘Ventana’, similar in shape and number to ‘Benicia’ and ‘Camarosa’. The stipule length is somewhat longer for ‘Fronteras’ than for the comparison cultivars.

TABLE 1 Foliar and plant characteristics for ‘Fronteras’, ‘Camarosa’, ‘Ventana’, and ‘Benicia’. Cultivar Foliar Character ‘Camarosa’ ‘Ventana’ ‘Benicia’ ‘Fronteras’ Plant height (mm) mean 227 277 245 313 range 190-320 250-300 220-260 300-330 Plant spread (mm) mean 368 425 414 421 range 300-465 375-525 360-500 345-485 Mid-tier leaflet Length (mm) mean 85 89 80 83 range 70-95  80-110 70-90 80-90 Width (mm) mean 79 77 80 73 range 65-90 70-90 75-80 60-90 Mid-tier leaf Length (mm) mean 230 231 264 247 range 200-290 180-260 220-310 200-280 Width (mm) mean 143 153 161 141 range 120-170 140-160 150-180 120-160 Leaf components Petiole length (mm) mean 110 113 136 141 range  90-150  80-120 110-160 110-160 Petiole diameter (mm) mean 3.6 5.3 4.9 4.6 range 3-4 4-7 4-6 4-5 Petiolule length (mm) mean 5.1 6.9 5.3 5.7 range 4-6 6-8 4-6 4-7 #leaflets/leaf 3 3 3, rarely 4 or 3 5 Leaf convexity most flat to flat to very flat to flat to slight concave concave concave concave Serrations number/leaf 20.8 20.6 20.5 20.1 range 19-23 18-25 18-23 18-22 shape semi-pointed semi-pointed round to round to semi- semi-pointed pointed Leaf pubescence light- moderate- moderate- moderate moderate heavy light Petiole pubescence density heavy moderate- heavy moderate- heavy heavy direction perpendicular perpendicular perpendicular perpendicular to acropetal to acropetal Petiole color (Munsell) 2.5 GY 8/9 7.5 GY 9/4 7.5 GY 8/10 2.5 GY 7/10 Stipule length (mm) mean 27.2 24.0 31.1 37.5 range 20-34 20-30 25-40 30-40 Stipule color core 2.5 Y 6/8 2.5 GY 8/9 2.5 Y 9/4 7.5 GY 8/7  margms 7.5 Y 6/7   5 GY 8/8 5 GY 8/8   5 GY 8/8  Stolon base diameter (mm) 11.7 15.2 16.5 13.2 Stolons per nursery mother 22.7 18.8 22.9 23.0 plant Venation pattern pinnate pinnate pinnate pinnate color 7.5 GY 8/7 7.5 GY 9/4 7.5 GY 8/7 2.5 GY 9/8 

Disease and Pest Reaction:

‘Fronteras’ is moderately resistant to powdery mildew (Sphaerotheca macularis), moderately susceptible to Anthracnose crown rot (Colletotrichum acutatum), and moderately resistant to Verticillium wilt (Verticillium dahliae), Phytophthora crown rot (Phytophthora cactorum) and common leaf spot (Ramularia tulasnei) (Table 2). When treated properly, it has tolerance to two-spotted spider mites (Tetranychus urticae) equal to that for the comparison cultivars. ‘Fronteras’ is tolerant to strawberry viruses encountered in California.

TABLE 2 Disease resistance scores for ′Fronteras′ and three comparison cultivars; all scores were obtained in evaluations conducted in 2012-2013. Phytophthora Verticillium Colletotrichum Resistance Score Resistance Score Resistance Score Genotype (5 = best) (5 = best) (5 = best) ′Cam arosa′ 3.6 2.8 2.3 ′Ventana′ 2.1 2.9 3.0 ′Benicia′ 3.5 1.6 2.5 ′Fronteras′ 4.1 3.7 2.5

Flowering, Fruiting, Fruit, and Production Characteristics:

‘Fronteras’ is similar to other California short-day strawberry cultivars (e. g. ‘Ventana’, ‘Camarosa’, and ‘Benicia’) in that it will flower over an extended period and into spring or summer, given appropriate local temperature and horticultural conditions. With most planting treatments ‘Fronteras’ produces fruit slightly later than ‘Ventana’ and ‘Benicia’ and earlier than for

‘Camarosa’. Comparative statistics for flower and fruit characters near mid-season are given for the four cultivars in Table 4. The primary flowers for ‘Fronteras’ are slightly larger than for ‘Camarosa’ but smaller than ‘Ventana’ and ‘Benicia’ with a calyx that is distinctly larger than the corolla on primary fruit. The calyx for ‘Fronteras’ varies in position but frequently has a slight indent early in the season and is even with the fruit later in the season; each primary flower has 5-7 petals, similar to the comparison cultivars on average. The fruit shape for ‘Fronteras’ is consistent throughout the season, and is typically medium to long conic, with a tendency to be somewhat cylindrical and blunt. It is easily distinguished by fruit shape from ‘Camarosa’ (shortened and flattened conic), or ‘Ventana’ (medium symmetrical conic), and ‘Benicia’ (often flattened). Fruit size for ‘Fronteras’ is substantially larger than for the comparison cultivars.

External fruit color for ‘Fronteras’ is similar to that for ‘Camarosa’, lighter than for ‘Benicia’, and darker than for ‘Ventana’; internal color for ‘Fronteras’ is somewhat lighter than for the comparison cultivars (Table 3). Achenes vary from yellow to dark red, and are even with the fruit surface or slightly indented.

TABLE 3 Foliar and fruit color characteristics for ′Fronteras′ and three comparison cultivars. Cultivar Color Character ′Camarosa′ ′Ventana′ ′Benicia′ ′Fronteras′ Leaf color (CIELAB) Adaxial L* mean 38.3 39.2 35.0 38.3 range 37.3-39.8 36.0-41.1 33.3-36.4 34.8-41.1 a* mean −12.2 −14.3 −11.7 −13.0 range  −9.5-−15.5 −12.9-−16.7 −10.3-−13.5 −11.3-−15.6 b* mean 16.9 20.6 16.9 18.7 range 13.3-19.9 17.3-24.8 13.1-21.7 13.8-22.6 Munsell 5 GY 5/5 2.5 GY 6/8 5 GY 5/6  5 GY 4/3 Abaxial L* mean 52.5 53.2 48.5 48.9 range 51.3-54.6 51.8-54.6 41.7-52.3 40.2-51.2 a* mean −13.1 −14.2 −13.5 −14.1 range −11.4-−14.9 −13.9-−14.7 −11.9-−16.8 −13.0-−15.1 b* mean 20.5 21.7 20.0 21.4 range 18.9-22.4 20.3-23.3 17.9-21.9 20.0-21.9 Munsell 7.5 GY 8/7 10 GY 8/7 7.5 GY 5/7 10 GY 7/8 Fruit color (CIELAB) External L* mean 38.6 38.1 36.0 36.9 range 34.7-42.7 37.6-39.0 34.2-37.5 35.5-37.3 a* mean 34.4 33.4 31.2 37.3 range 33.6-36.2 29.4-38.7 26.6-36.3 35.1-39.9 b* mean 22.5 19.2 14.2 19.2 range 18.8-29.3 17.8-21.1 10.6-17.3 16.7-19.0 Munsell 7.5 R 4/11   5 R 4/12 2.5 R 4/0 7.5 R 4/11 Internal L* mean 50.2 48.6 44.0 55.7 range 46.6-53.3 46.2-52.3 40.8-47.0 50.4-60.4 a* mean 30.8 28.9 30.9 20.9 range 25.6-35.4 23.5-33.0 27.8-33.6 18.1-25.9 b* mean 30.1 31.3 27.5 25.4 range 28.0-32.0 30.6-32.5 24.6-28.8 19.6-30.7 Munsell 7.5 R 5/13 7.5 R 6/13 5 R 4/2 7.5 R 5/3  Achene color 2.5 Y 7/10 10 Y 8/11 5 R 3/7 2.5 R 8/12 Munsell

TABLE 4 Flower and fruit characters for ′Fronteras′ and three comparison cultivars. Cultivar Character ′Camarosa′ ′Ventana′ ′Benicia′ ′Fronteras′ Petal number mean 5.8 6.2 6.1 5.9 range 5-7 5-7 5-7 5-7 Petal shape apex truncate to truncate to truncate to truncate to slightly slightly slightly slightly base obtuse obtuse obtuse obtuse margin attenuate attenuate attenuate attenuate entire entire entire entire Petal length (mm) mean 11.5 13.3 11.7 13.5 range 10-13 11-15  8-13 13-15 Petal width (mm) mean 12.0 14.6 14.4 12.6 range 10-14 13-16  8-13  8-14 Flower position most even even to even to most even (relative to foliage) some exposed exposed some exposed interior Calyx diam.(mm) mean 40.4 47.0 50.8 48.3 range 33-47 40-50 47-53 44-54 Corolla diam.(mm) mean 26.1 39.0 39.6 31.3 range 23-31 35-45 39-41 29-38 Sepal length (mm) mean 14.3 16.6 16.4 14.6 range 12-18 14-19 13-20 11-17 Sepal width (mm) mean 8.3 8.4 8.4 9.3 range  7-10  7-10  7-10  7-11 Sepal color (Munsell) 5 GY 7/10 5 GY 5/5 10 GY 8/7 5 GY 5/6 Pedicel length (mm) mean 155 115 183 125 range 130-180  90-140 150-210  90-170 Pedicel diameter (mm) mean 2.7 3.5 3.7 4.7 range 2-4 3-4 3-5 4-6 Pedicel color 7.5 GY 8/7 5 GY 8/9 2.5 GY 8/9 7.5 GY 6/8 Fruit shape Fruit length (mm) mean 46.0 48.4 46.5 54.5 range 40-48 47-52 41-52 51-58 Fruit width (mm) mean 37.4 42.6 42.4 46.7 range 33-46 40-46 36-46 42-54 Length/ width ratio 1.26 1.17 1.08 1.15 range 1.0-1.4 1.1-1.2 1.0-1.2 1.0-1.2 subjective Obovate-flat Medium Medium Medium-long conic conic conic Primary/secondary fruit comparison size (subjective) 50-70% 55-75% 55-65% 60-80% shape similar similar shape similar shape similar shape shape, more conic Extent/size of hollow core small-absent small small-absent small-absent Calyx position indented- indent- even-indented Indented-even neck reflexed size relative to fruit equal or less equal or less equal or equal or less than fruit than fruit greater than than fruit diameter diameter fruit diameter diameter Seed position indented- mostly even even-indented indented- extruded extruded Adherence of Calyx to Fruit weak intermediate weak intermediate Flower and plant measurements obtained on April, 2012, fruit measurements May 10-20, 2012.

‘Fronteras’ has been tested under a variety of cultural regimes, and optimal performance is obtained when nursery treatments and nutritional programs similar to those for ‘Camarosa’, ‘Ventana’, and ‘Benicia’ are used. In general, plants of ‘Fronteras’ are greater in vigor than the comparison cultivars with very early season planting. ‘Fronteras’ retains excellent fruit quality in summer planting systems.

When treated with appropriate planting regimes, ‘Fronteras’ has substantially larger sized fruit and produces individual-plant yields greater than any of the comparison cultivars (Table 5). Commercial appearance ratings have also been substantially better than those for all of the comparison cultivars, especially in comparison with ‘Camarosa’. Fruit for ‘Fronteras’ is similar in firmness to fruit from ‘Ventana’, less firm than the other comparison cultivars. Subjectively, ‘Fronteras’ has excellent flavor. The fruit will be exceptional for both fresh market and processing, and will be useful for home garden purposes.

TABLE 5 ′Fronteras′ and three comparison cultivars evaluated at the Watsonville Research Facility in 2010-12. All plants for these trials were harvested from a commercial nursery near Macdoel, CA on October 15-16, and transplanted after 6-7 days supplemental storage. Fruit harvest was initiated in early April and continued through the last week of August. (52″ 2-row beds, 17,300 plants/acre). Appearance Fruit Yield Score Size Item (g/plant) (5 = best) (g/fruit) Firmness ′Camarosa′ 1,815 2.8 27.1 11.6 ′Ventana′ 2,080 3.3 30.1 10.2 ′Benicia′ 1,649 3.4 33.1 11.1 ′Fronteras′ 2,793 4.2 35.1 11.1 

What is claimed is:
 1. A new and distinct cultivar of strawberry plant having the characteristics substantially as described and illustrated herein. 